Apparatus and method for open thread, reusable, no-waste collapsible tube dispensers

ABSTRACT

The invention includes a method of using a cap containing an internal thread form matching an external thread form on a flexible throat for a collapsible tube enclosing at least one contained product. Twisting the cap engages the internal thread form and the external thread form. These collectively urge the cap and the flexible throat to seal the contained product into the collapsible tube. Deforming the flexible throat through squeezing the collapsible tube dispenses essentially all the product. The collapsible tube may preferably include an external thread form on a flexible throat coupled to a flexible shoulder. The external thread form mates to a cap with an internal thread form urging the flexible throat to seal against the cap when the cap is twisted onto the flexible throat. The flexible throat and flexible shoulder flatten to dispense essentially all of the product.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 10/928,676, filedAug. 26, 2004, which is incorporated herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to open thread screw and cap mechanisms withparticular application to forming collapsible tube dispensers.

2. Background Information

The earliest collapsible tube dispensers in the U.S. patent databasedate from the early nineteenth century. Since that time, there has beencontinued innovation, leading to the various collapsible tube dispensersused for pharmaceuticals, personal care products, toothpaste, foods,artist's paints, glues, hazardous chemicals, grease products and viscousplastics, to name some of the more common uses of these tubes. As usedherein, personal care products include, but are not limited to,cosmetics, facial care products, skin care products, and/or hair careproducts.

There are problems with the collapsible tube technologies of the priorart. They do not lend themselves both to being reusable and supportingthe complete, controlled dispensing of their contents. As the term isused herein, reusable will refer to the capability to dispense small, orcontrolled, portions of the contents multiple times, perhaps ondifferent occasions. Reusable may further refer to the capability torefill the contents multiple times. And reusable may further refer to acontainer, which can be cleaned, and refilled with differing contents.

One prior art collapsible tube dispenses all the tube's contents and isreuseable. The tube is not cylindrical but a two-sided pouch of softplastic material. The tube has a mechanism of closing the throat,requiring no conventional screw and cap. The throat contains a softplastic sheet insert that effectively sucks itself closed when pressureis released. This tube may be limited to applications in which there isno unexpected or forceful pressure applied to the tube. Exampleapplications where it is not applicable include being packed in asuitcase, or purse, since the closure responds to finger pressure. Thetube may also be limited to applications in which a high degree ofbarrier to the environment is not critical, such as pharmaceuticals,because the opening does not clean itself when closing except to thedegree that it draws contents outside the tube to the inside of thetube. It may be undesirable for personal care products or other productsdemanding a high degree of aesthetic features, such as oversized capsallowing the tube to stand vertically.

There are some one-time use containers made essentially of a squeezetube with a narrow end, which is cut to open the tube. All of thecontents are then squeezed out, and the tube is discarded. Theseone-time use containers are not reusable, and represent a significantamount of overhead both for the manufacturer and for the ecology ofpeople and systems, which must cope with these discarded containers.

With the exception of some one-time use containers, collapsible tubedispensers typically possess a rigid shoulder and a rigid throat. Therigid throat provides an exterior, rigid screw. This exterior rigidscrew mates with a cap providing a matching interior screw pattern. Whenthe cap is screwed onto the exterior screw of the throat, a seal isformed, which seals in the contents of the collapsible tube.

For the last century or two, screws have been built with either threadsthat taper away from the body, or remain of constant thickness. Thesescrew threads will be referred to herein as open threads. Up until now,using these open thread screws requires that the throat of a collapsibletube be essentially rigid. An essentially rigid throat on a collapsibletube dispenser virtually guarantees that some of the tube contents willnot readily leave the tube, causing the tube to waste some of itscontents. The rigid shoulder further guarantees this waste.

The use of tubes for carrying food in sports and wilderness explorationenvironments is known. None on the market, however, are both reusableand completely collapsible. Thus, they do not dispense all theircontents. A refillable tube that does dispense all its contents isespecially desirable when food is otherwise scarce.

FIG. 1A shows a prior art exterior screw 20 with a prior art externalthread form 22. The prior art external thread form 22 is shown in anexpanded view through the following examples shown in Figures 1B and Cwith a matching internal thread form 24.

There is a local coordinate system in FIG. 1A, which will be usedthroughout this document. The z axis 10 extends through the center ofthe cylinder of the prior art exterior screw 20, and is the central axisof the cylinder. The r axis 12 is the radial direction of the thread ata point, which, for the sake of discussion, is referred to as threadpoint 22 in Figure 1A. The n axis 14 is normal to the thread point 22.When the screw is turned in the n direction, it engages more of thethreads.

The engagement of an exterior screw thread and matching interior screwis shown in the expanded view of the prior art open screw thread 22 inFigure 1A. The expanded view is a cross-section of the threads taken inthe plane of the z axis 10 and the r axis 12.

Figure 1B shows an example of FIG. 1A using a standard acme thread forthe external thread form 22 and the matching internal thread form 24. Afirst external acme thread 22-1 matches the first internal acme thread24-1. A second external acme thread 22-2 with the second internal acmethread 24-2.

FIG. 1C shows an example of FIG. 1A using a standard buttress thread forthe external thread form 22 and the matching internal thread form 24. Afirst external buttress thread 22-3 matches the first internal buttressthread 24-3. A second external buttress thread 22-4 with the secondinternal buttress thread 24-4.

FIG. 1D shows an example of FIG. 1A using a box thread for the externalthread form 22 and the matching internal thread form 24. A firstexternal box thread 22-5 matches the first internal box thread 24-5. Asecond external box thread 22-6 with the second internal box thread24-6.

One skilled in the art will recognize that FIGS. 1B to 1D show some ofthe many variations in open threads in use today. Other commonly usedthreads include various “V” shaped threads, as well as variations inangles of the walls, variations in the shape of the peaks and troughs ofthe threads.

To summarize, what is needed is a reusable collapsible tube, which candispense essentially all of its contents. There is a need for reusablecollapsible tubes which may be reopened to load the contents,particularly for food containers for use in travel and wildernesssettings.

SUMMARY OF THE INVENTION

The invention includes a method of using a cap containing an internalthread form matching an external thread form on a flexible throat for acollapsible tube enclosing at least one contained product. Twisting thecap engages the internal thread form and the external thread form. Thesecollectively urge the cap and the flexible throat to seal the containedproduct into the collapsible tube. Deforming the flexible throat throughsqueezing the collapsible tube dispenses essentially all of thecontained product.

This method of using a collapsible tube permits dispensing essentiallyall of the contained product. The collapsible tube is also reusable,permitting its use in a variety of fields where today everyone is forcedto waste the last part of the contained product. This is valuable insuch diverse areas of application as pharmaceuticals, personal careproducts, toothpaste, foods, artist's paints, glues, hazardouschemicals, grease products, and viscous plastics.

The collapsible tube may preferably include an external thread form on aflexible throat coupled to a flexible shoulder mating to a collapsibletube body. The external thread form mates to a cap with an internalthread form urging the flexible throat to seal against the cap when thecap is twisted onto the flexible throat. The flexible throat and theflexible shoulder flatten with the collapsible tube body to dispenseessentially all of the product.

The external thread form may preferably include at least two externalopen threads. These external open thread preferably include at least onebreak. The break may form a column, a canted column, or a fluted column.The fluted column may widen toward the flexible shoulder, or away fromthe flexible shoulder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a prior art exterior screw with a prior art externalthread form;

FIG. 1B shows a prior art example of FIG. 1A using a standard acmethread for the external thread form and the matching internal threadform;

FIG. 1C shows a prior art example of FIG. 1A using a standard buttressthread for the external thread form and the matching internal threadform;

FIG. 2A shows a top view of a collapsible tube showing a first breakforming a canted column;

FIG. 2B shows a front view of the collapsible tube in FIG. 2A showing afirst break and a second break;

FIG. 3A shows a side view of the collapsible tube in FIG. 2A with thefirst break forming rectangular column;

FIG. 3B shows a detail of FIG. 3A showing the flexible throat with athread form including at least two, and in this case four open threads,which could be by way of example, external acme threads, externalbuttress threads, external V threads, external box threads, orcombinations or modifications of these well known open threads;

FIG. 3C shows the first break forming a fluted column expanding towardthe flexible shoulder;

FIG. 3D shows the first break 600 forming a fluted column expanding awayfrom the flexible shoulder;

FIG. 4 shows the collapsible tube as in FIGS. 2B to 3B with a cap;

FIG. 5A shows the collapsible tube of FIG. 4 with the cap engaged andfilled with at least one content;

FIG. 5B shows a cross section of FIG. 5A of the collapsible shoulder,flexible throat engaging the internal thread form and the externalthread form using buttress threads;

FIG. 6A shows the collapsible tube of FIG. 4 with a second cap engagedand filled with contents;

FIG. 6B shows a cross section of FIG. 6A with the collapsible shoulderand flexible throat of FIG. 5B engaging a hollow version of the secondcap;

FIG. 7 shows a cross section of FIG. 6A with the collapsible shoulderand flexible throat of FIG. 5B engaging a filled version of the secondcap;

FIGS. 8A to 8D show the front view of a collapsible tube with none, one,two, and three breaks in its external threads, respectively;

FIGS. 9A to 9D shows the front view of the collapsible tubes of FIGS. 8Ato 8D partially deformed by squeezing the collapsible tube bodies andflexible shoulders;

FIGS. 10A to 10D show the further squeezing of the collapsible tube ofFIGS. 8A and 9A, which has no breaks in its external threads;

FIGS. 10E to 10H show the further squeezing of the collapsible tube ofFIGS. 8C and 9C, which has a first break and a second break;

FIGS. 11A to 11D show the side view of the squeezing of the collapsibletube shown in FIGS. 9C, and 10E to 10H, with the contained product beingdispensed.

DETAILED DESCRIPTION

The invention's collapsible tubes preferably utilize a flexible shoulder504, shown in FIGS. 2A to 11D, being squeezed toward the flexible throat502, which concentrates the contents 900 so that very little is wastedin normal use. FIGS. 2A to 11D show various embodiments of a collapsibletube 500, including at least a first break 600 forming various columnsin the radial axis of the flexible throat 502.

FIG. 2A shows a top view of the collapsible tube 500 showing a firstbreak 600 forming a canted column. FIG. 2B shows a front view of thecollapsible tube 500 in FIG. 2A showing a first break 600 and a secondbreak 602. FIG. 3A shows a side view of the collapsible tube 500 in FIG.2A with the first break 600 forming rectangular column.

FIG. 3B shows a detail of FIG. 3A showing the flexible throat 502 with athread form including at least two, and in this case four open threads.These threads could, be by way of example, external acme threads,external buttress threads, external V threads, external box threads, orcombinations or modifications of these well known open threads.

FIG. 3C shows the first break 600 forming a fluted column expandingtoward the flexible shoulder.

FIG. 3D shows the first break 600 forming a fluted column expanding awayfrom the flexible shoulder.

FIG. 4 shows the collapsible tube as in FIGS. 2B to 3B with a cap 800.

FIG. 5A shows the collapsible tube of FIG. 4 with the cap 800 engagedand filled with at least one content.

FIG. 5B shows a cross section of FIG. 5A of the collapsible shoulder504, flexible throat 502 engaging the internal thread form and theexternal thread form. The internal thread form includes internalbuttress threads 804-1 to 804-4. The external thread form includesexternal buttress threads 702-1 to 702-4. The internal thread form andthe external thread form collectively urge the cap 800 and the flexiblethroat 502 to seal the contained product into the collapsible tube. Thecap 800 further, preferably includes an interior bulge 802 which actsupon the flexible throat 502 to urge the flexible throat 502 to engagethe internal thread form and the external thread form.

As shown and discussed herein, the threads on the flexible throat 502,the flexible shoulder 504, and when applicable, the collapsible tubebody 506, are preferably made of flexible materials. These flexiblematerials include, but are not limited to, at least one thermosetelastomeric and/or thermoplastic elastomer. Elastomeric plasticsinclude, but not limited to, urethane, polyvinyl chloride, ThermoPlasticelastomer Olefin (TPO), Thermal PolyVinyl chloride (TPV),ThermoPlasRubber (TPR) and/or Silicone based compounds. An elastomericplastic is typically a polymer blend or compound, which above itsmelting temperature, exhibits a thermoplastic behavior enabling it to beshaped into a fabricated article, such as a collapsible tube or cap.When the article is within its design temperature range, it exhibitselastomeric behavior without cross-linking during fabrication. Thefabrication process is reversible. The article can be reprocessed andremolded. The method of making these collapsible tubes 500 may include,but is not limited to, using a mold, into which the material(s) areinjected and/or blown. The material may be injected one or more times.When material is injected more than one time, the process is often knownas a multi-shot molding.

In FIGS. 5B, 6B, and 7, the internal thread form slides along theexternal thread form, and the external thread form slides along theinternal thread form to slide along each other, when the internal threadform and the external thread form engage. After they engage, continuedsliding causes the internal thread form and the external thread form tolock, sealing the contained product into the collapsible tube.

One skilled in the art will recognize that various bumps and ridges inthe cap and throat may be used to enhance engagement. As used herein theengagement enhancing bumps and ridges are not part of the screw slidingoperations.

FIG. 6A shows the collapsible tube of FIG. 4 with a second cap 820engaged and filled with contents. FIG. 6B shows a cross section of FIG.6A with the collapsible shoulder 504 and flexible throat 502 of FIG. 5Bengaging a hollow version of the second cap 820. FIG. 7 shows a crosssection of FIG. 6A with the collapsible shoulder 504 and flexible throat502 of FIG. 5B engaging a filled version of the second cap 820. Note theinterior rim 822 included in the second cap 820 may preferably extend tobelow at least the first external thread 804-1 to aid in urging thereforming of the flexible throat 502. It may further preferred that theinterior rim 822 extend below the second external thread 804-2, etc. Oneskilled in the art will recognize that many variations in the caps 820and 800 are preferred in different situations, causing variation in atleast their size, shape, number of threads, and whether or not they arehollow.

FIGS. 8A to 8D show the front view of a collapsible tube with none, one,two, and three breaks in its external threads, respectively.

FIGS. 9A to 9D shows the front view of the collapsible tubes of FIGS. 8Ato 8D partially deformed by squeezing the collapsible tube bodies 506and flexible shoulders 504.

FIGS. 10A to 10D show the further squeezing of the collapsible tube ofFIGS. 8A and 9A, which has no breaks in its external threads.

FIGS. 10E to 10H show the further squeezing of the collapsible tube ofFIGS. 8C and 9C, which has a first break 600 and a second break 602.

FIGS. 11A to 11D show the side view of the squeezing of the collapsibletube shown in FIGS. 9C, and 10E to 10H, with the contained product 900being dispensed.

This method of using a collapsible tube permits dispensing essentiallyall of the contained product. The contained product may be any of thefollowing: a pharmaceutical, a personal care product, a toothpaste, afood, an artist's paint, a glue, a hazardous chemical, a grease product,and/or a viscous plastic.

Substances will be referred to herein as viscous plastics when they areviscous enough to be pressed out of a collapsible squeeze tube to form ablob or a line for various purposes, such as caulk or other sealants,compounds used to create a braille letter, or other identifying mark onitems for the blind, or decorative substances that are not simply paintbut create texture and mass when applied, or compounds that dry whenexposed to air forming durable shapes, marks, seals, decorations, andthe like.

The collapsible tube 500 may have the tube closure 510, repeatedlyopened and sealed shut by using a mechanical device (sometimes known asa key). Versions of key typically include a plastic cylinder with a slitin its center that slides over the open end of the tube, rolls towardthe flexible throat 504 of the collapsible tube 500 to seal the tubeclosure 510, and locks itself in the closed position.

The collapsible tube 500 shown in the preceding FIGS. may preferably bemade of at least one flexible thermoset elastomeric and/or flexiblethermoplastic elastomer. Elastomeric plastics include, but not limitedto, urethane, polyvinyl chloride, ThermoPlastic elastomer Olefin (TPO),Thermal PolyVinyl chloride (TPV), ThermoPlasRubber (TPR) and/or Siliconebased compounds. The cap to which the flexible threads mate may also bemanufactured using existing collapsible tube manufacturing technologyand materials.

The cap 800 and the cap 820 shown in the preceding FIGS. may preferablybe made of at least one rigid thermoset elastomeric and/or rigidthermoplastic elastomer. Elastomeric plastics include, but not limitedto, urethane, polyvinyl chloride, ThermoPlastic elastomer Olefin (TPO),Thermal PolyVinyl chloride (TPV), ThermoPlasRubber (TPR) and/or Siliconebased compounds. The cap to which the flexible threads mate may also bemanufactured using existing cap molding technology and materials. Theinterior bulge 802 on the cap that inserts into the flexible throat 502may also be a standard cap design. The interior rim 822 on the cap thatinserts into the flexible throat 502 may also be a standard cap design.These caps may also be made from conventional cap materials.

The preceding embodiments have been provided by way of example and arenot meant to constrain the scope of the following claims.

1. A collapsible tube for containing at least one product, comprising:an external thread form on a flexible throat coupled to a flexibleshoulder, whereby said external thread form mates with an internalthread form, included in a cap, urging said flexible throat to sealagainst said cap when said cap is twisted onto said flexible throat, andsaid flexible throat and said flexible shoulder flatten to dispenseessentially all of said product, said external thread form furthercomprises: at least two external open threads, each of said externalopen threads possesses at least one break, and all of said breaks of allof said external open threads, form at least one column in the radialaxis of said flexible throat.
 2. The collapsible tube of claim 1,further comprising: said flexible shoulder mating to a collapsible tubebody, whereby said flexible throat and said flexible shoulder flattenwith said collapsible tube body to dispense essentially all of saidproduct.
 3. The collapsible tube of claim 1, further comprising: saidflexible shoulder mating to itself.
 4. The collapsible tube of claim 1,wherein said external open thread involves at least one of an externalacme thread, an external buttress thread, an external V thread, and anexternal box thread.
 5. The collapsible tube of claim 1, wherein saidcollapsible tube contains at least two contained products.
 6. Thecollapsible tube of claim 1, wherein said contained product is at leastone member of the group consisting of: pharmaceutical product, apersonal care product, a paint product, a toothpaste product, a foodproduct, a glue product, a hazardous chemical, a grease product, and aviscous plastic.
 7. A cap for a collapsible tube, comprising: aninternal thread form for mating with an external thread form on aflexible throat to urge said flexible throat to seal against said capwhen said cap is twisted; said cap further comprising one of: aninterior bulge to act upon said flexible throat to urge said flexiblethroat to engage said internal thread form and said external threadform; and an interior rim to act upon said flexible throat to urge saidflexible throat to engage said internal thread and said external threadform.
 8. Said cap of claim 7, wherein said cap is not flexible.
 9. Saidcap of claim 8, wherein said cap is rigid.